The invention relates to magnetic disk drive units or machines of a type adapted to accommodate disk-jacket assemblies, and more particularly the invention relates to mechanism for draining off accumulations of static electricity carried by the jacket of such an assembly.
Magnetic disk-jacket assemblies have been previously proposed as, for example, in U.S. Pat. No. 3,668,658 issued June 6, 1972 to Ralph Flores et al. In addition, machines for accommodating such disk-jacket assemblies have been previously proposed, such as for example in U.S. Pat. No. 3,846,836 issued on Nov. 5, 1974 to Philip R. Masse et al. It has been found that if the jacket of such a disk-jacket as is described in U.S. Pat. No. 3,668,658 is formed of a material having high electrical resistance, such as polyvinyl chloride acetate, such jackets accumulate electrical charges which cause spurious signals to be applied to a transducer in electrical energy transferring relationship with respect to the disk. Such a type of high electrical resistive material is particularly suitable for use with such jackets due to high impact resistance, the ability to heat seal the parts thereof together, etc. The problem has been found particularly acute when transducers composed mainly of electrical insulating material are used, and such transducers have been found particularly desirable due to their low cost, better electrical response, etc.